1. Technical Field
The present disclosure generally relates to battery charging and in particular to enabling capacity based pre-charging of batteries in an information handling system.
2. Description of the Related Art
As the value and use of information continue to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes, thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Some information handling systems utilize batteries as either a primary power source or as a backup power source. One example of an information handling system that uses batteries is a laptop computer. The battery allows the laptop computer to be used in a mobile setting without being connected to a source of utility power. Lithium ion (Li-ion) batteries are widely used in laptop computers. Li-ion batteries can be formed from one or more Li-ion cells and offer a high energy density and long life.
However, Li-ion cells also have several problems. For example, Li-ion cells can become over-discharged for several reasons, such as leakage current in the battery circuitry or because of an internal short. In some cases, recovery from an over-discharged state may not be possible. Li-ion cells require special handling to recover from an over-discharged state and recovery is dependent upon the cell voltage. If a Li-ion cell is over-discharged, there is a possibility of anodic dissolution and extraction of copper (Cu) to form free Cu2+ ions. When the cell is subsequently charged, under the voltage difference between the cathode and anode, the Cu2+ ions can penetrate through an internal separator and cause copper shunts. This internal short circuit may lead to the activation of safety devices within the cell causing one of a permanent cell failure or blowing of a fuse within a battery protection circuit.
After a Li-ion cell has become over discharged, a pre-charging process is required prior to the application of full charging current. If the battery is deeply discharged, a small pre-conditioning charge of approximately 10 percent of the full charge current is applied to check the cell before applying full charging current. After pre-charging, the cell is returned to a standard operating mode and is charged according to the regular charging procedure.